/Engine/Source/Editor/UnrealEd/Public/Kismet2/KismetEditorUtilities.h
Run over the components references, and then NULL any that fall outside this blueprint's scope (e.g. components brought over after reparenting from another class, which are now in the transient package)
static void StripExternalComponents ( class [UBlueprint](API\Runtime\Engine\Engine\UBlueprint) * Blueprint )